/*
 * Tencent is pleased to support the open source community by making TBase available.  
 * 
 * Copyright (C) 2019 Tencent.  All rights reserved.
 * 
 * TBase is licensed under the BSD 3-Clause License, except for the third-party component listed below. 
 * 
 * A copy of the BSD 3-Clause License is included in this file.
 * 
 * Other dependencies and licenses:
 * 
 * Open Source Software Licensed Under the PostgreSQL License: 
 * --------------------------------------------------------------------
 * 1. Postgres-XL XL9_5_STABLE
 * Portions Copyright (c) 2015-2016, 2ndQuadrant Ltd
 * Portions Copyright (c) 2012-2015, TransLattice, Inc.
 * Portions Copyright (c) 2010-2017, Postgres-XC Development Group
 * Portions Copyright (c) 1996-2015, The PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, The Regents of the University of California
 * 
 * Terms of the PostgreSQL License: 
 * --------------------------------------------------------------------
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without a written agreement
 * is hereby granted, provided that the above copyright notice and this
 * paragraph and the following two paragraphs appear in all copies.
 * 
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
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 * POSSIBILITY OF SUCH DAMAGE.
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 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
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 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 * 
 * 
 * Terms of the BSD 3-Clause License:
 * --------------------------------------------------------------------
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 * 
 * 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation 
 * and/or other materials provided with the distribution.
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 * 3. Neither the name of Tencent nor the names of its contributors may be used to endorse or promote products derived from this software without 
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS 
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
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 */
/*
 * pgp-mpi.c
 *      OpenPGP MPI helper functions.
 *
 * Copyright (c) 2005 Marko Kreen
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * contrib/pgcrypto/pgp-mpi.c
 */
#include "postgres.h"

#include "contrib/pgcrypto/px.h"
#include "contrib/pgcrypto/pgp.h"

int
pgp_mpi_alloc(int bits, PGP_MPI **mpi)
{
    PGP_MPI    *n;
    int            len = (bits + 7) / 8;

    if (bits < 0 || bits > 0xFFFF)
    {
        px_debug("pgp_mpi_alloc: unreasonable request: bits=%d", bits);
        return PXE_PGP_CORRUPT_DATA;
    }
    n = crypt_alloc(sizeof(*n) + len);
    n->bits = bits;
    n->bytes = len;
    n->data = (uint8 *) (n) + sizeof(*n);
    *mpi = n;
    return 0;
}

int
pgp_mpi_create(uint8 *data, int bits, PGP_MPI **mpi)
{
    int            res;
    PGP_MPI    *n;

    res = pgp_mpi_alloc(bits, &n);
    if (res < 0)
        return res;
    memcpy(n->data, data, n->bytes);
    *mpi = n;
    return 0;
}

int
pgp_mpi_free(PGP_MPI *mpi)
{
    if (mpi == NULL)
        return 0;
    crypt_memset(mpi, 0, sizeof(*mpi) + mpi->bytes);
    crypt_free(mpi);
    return 0;
}

int
pgp_mpi_read(PullFilter *src, PGP_MPI **mpi)
{
    int            res;
    uint8        hdr[2];
    int            bits;
    PGP_MPI    *n;

    res = pullf_read_fixed(src, 2, hdr);
    if (res < 0)
        return res;
    bits = ((unsigned) hdr[0] << 8) + hdr[1];

    res = pgp_mpi_alloc(bits, &n);
    if (res < 0)
        return res;

    res = pullf_read_fixed(src, n->bytes, n->data);
    if (res < 0)
        pgp_mpi_free(n);
    else
        *mpi = n;
    return res;
}

int
pgp_mpi_write(PushFilter *dst, PGP_MPI *n)
{
    int            res;
    uint8        buf[2];

    buf[0] = n->bits >> 8;
    buf[1] = n->bits & 0xFF;
    res = pushf_write(dst, buf, 2);
    if (res >= 0)
        res = pushf_write(dst, n->data, n->bytes);
    return res;
}

int
pgp_mpi_hash(PX_MD *md, PGP_MPI *n)
{
    uint8        buf[2];

    buf[0] = n->bits >> 8;
    buf[1] = n->bits & 0xFF;
    px_md_update(md, buf, 2);
    px_md_update(md, n->data, n->bytes);

    return 0;
}

unsigned
pgp_mpi_cksum(unsigned cksum, PGP_MPI *n)
{
    int            i;

    cksum += n->bits >> 8;
    cksum += n->bits & 0xFF;
    for (i = 0; i < n->bytes; i++)
        cksum += n->data[i];

    return cksum & 0xFFFF;
}
